• Journal of Korean Society for Quality Management
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• v.40 no.4
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• pp.431-440
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• 2012

Purpose: In this paper we propose modified Notz designs which are useful to experimenters who want to adopt the sequential experimentation strategy and to estimate second-order regression model with as few experimental points as possible. Methods: We first present the design matrices and design points in two or three dimensional spaces for such small sized second-order designs as small composite, hybrid, and Notz designs. Modified Notz designs are proposed and compared with some response surface designs in terms of the total number of experimental points, the estimation capability criteria such as D- and A-optimality. Results: When sequential experimentation is necessary, the modified Notz designs are recommendable. Conclusion: The result of this paper will be beneficial to experimenters who need to do experiments more efficiently, especially for those who want to reduce the time of experimentation as much as possible to develop cutting-edge products.

• Journal of Korean Society for Quality Management
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• v.49 no.1
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• pp.31-45
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• 2021

Purpose: A noncentral composite design method is to be developed to explore farther region for the first factorial design. A general guideline for sequential experimentation is provided. Methods: (1) A non-overlapping noncentral composite design (NNCD) is developed, in which the second factorial design shares one design point that indicates the best response value in the first factorial design. (2) Four composite designs are compared in terms of the four design evaluation criteria, which are D-, A, G, and I-optimality. (3) A follow-up design strategy is suggested based on the interaction effect, direction of improvement, number of factors. Results: (1) NNCD and model building method are presented, which is useful for exploring farther region from first factorial design block. (2) The performances of the four composite designs are compared. (3) A follow-up design strategy is suggested. Conclusion: (1) NNCD will be useful to explore farther region for the first factorial design. (2) A follow-up design strategy can be beneficial to the experimental practitioners for product and process design and improvement.

• Communications for Statistical Applications and Methods
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• v.9 no.3
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• pp.619-627
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• 2002

It is unpractical for the optimal design theory based on the given model and assumption to be applied to the real-world experimentation. Particularly, when the experimenter feels it necessary to consider multiple objectives in experimentation, its modified version of optimality criteria is indeed desired. The constrained optimal design is one of many methods developed in this context. But when the number of constraints exceeds two, there always exists a problem in specifying the lower limit for the efficiencies of the constraints because the “infeasible solution” issue arises very quickly. In this paper, we developed a sequential approach to tackle this problem assuming that all the constraints can be ranked in terms of importance. This approach has been applied to the polynomial regression model.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.4
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• pp.352-365
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• 2001

Two-level factorial designs are popular in industry due to their simplicity, efficiency, graphical interpretation, and flexibility in sequential experimentation. However, experimenters are often frustrated when they have factors with more than two levels. There have been some works on design of experiments with two- and four-level factors, which mostly deal with qualitative four-level factors. This paper discusses differences between qualitative and quantitative four-level factors. Optimal designs are provided for some designs with four-level quantitative and two-level factors.

• Journal of Korean Society for Quality Management
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• v.47 no.3
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• pp.631-639
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• 2019

Purpose: In this paper we present a case study of applying quick and easy experimental design approach to develop a Halogen free flame retardant material for cellular phone charger cable. Methods: We employ sequential experimentation of mixture design, verification design, and factorial design. A quick and easy approach is adopted based on data investigation and graphical method instead of strict statistical analysis, which helped enhancing smooth communication with the engineers and speeding up the development process. Results: Flame retardant material in pellet type produced from the optimal condition is transported to the customer and tested, to pass the customer retardancy criteria. Conclusion: The quick and easy experimental design approach is considered to be useful in this case study.

• Korean Institute of Interior Design Journal
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• v.19 no.5
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• pp.226-233
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• 2010

This study is to analyze and determine the emotional design on domestic rec-education space, in order to propose a way to design children rec-education space. A study is on reviewing needs and verify categories of emotional design through interior design of rec-education space, A study procedure will begin with theoretical proofing of children rec-education and move on to needs of emotional design in interior design and types of analysis for it. With this procedure, we will project adequate way for emotional characteristics in rec-education space and will analyze types of it from interior design of rec-education space in nine different domestic brands. With this background, we like to present methods and reveal characteristics of it. The conclusion on this study is described as followed. First, children rec-education space has positively carried types of emotional characteristics: experimental, continuity, and symbolism. Second, Some precondition; application through types of pattern, experimentation on light in space, continuity on linear interior space composition, symbolism in abstract implementation, and physical control over designed subject, has low effectiveness on creating emotional space by applying such scale matters. Third, the actual interior design subject matters and supporting facilities' textural accommodation is inadequately built for their majority, children, whether it is direct or indirect for contact. Forth, Even though to carry emotional space needs some kinds of story telling and prerequisite sequential space composition, there are lack of applicable space compositions. For this reason, it needs on going study in emotional space for children rec-education space. Last, there are needs for researching a depth understanding and presenting different characteristics of emotional interior design by brands.

• Tuberculosis and Respiratory Diseases
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• v.46 no.1
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• pp.75-81
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• 1999

Background : Recently, there are many patients with lipoid pneumonia by ingestion of shark liver oil in Korea, but only a few animal experimentations have been carried out. The purpose of this study is to evaluate sequential change of the lung after aspiration of shark liver oil and to provide the radiologic-pathologic correlation. Methods: A single intratracheal administration of shark liver oil was given to 14 white rabbits. They were then sacrificed sequentially from 1 week to 6 weeks after injection. We investigated the HRCT and pathologic findings Results: One was sudden death immediately after injection. Six of the 13 rabbits showed pneumonic infiltrations on the HRCT. There were air space consolidation with air-bronchogram on the HRCT of the first week. They were associated with the volume loss in the 4th week, and the traction bronchiectasis in the 6th week. The important pathologic findings were peribronchial alveolar inflammation with septal widening and cuboidal metaplasia of the alveolar wall. The number of macrophages in an alveoli was peaked in the second week and then gradually decreased. On the 6th week, we could find the proliferation of fibroblasts. Conclusion: We can prove the development of lipoid pneumonia after aspiration of squalene by animal experimentation, and the understanding of HRCT and pathologic findings may be helpful in proper evaluation of pneumonia due to aspiration of fish-extracted lipid.